Pros
Alternative is a great place to get your start in business like this. Management try very hard to make it a great place to work, and the office is as nice as it can be for its location (including a cafe and small gym). Always felt like I could pop into HR or my directors office if I ever needed to discuss anything. My particular managers were great in understanding our personal life and work life balance. While I was there, the CEO would hold quarterly Q&As in a very open form. The company would regularly cater or throw events for their employees.
Cons
Serious lack of growth. New positions aren't being created often, so you can hit your ceiling in a couple of years as far as career growth. While management try's to make it a progressive office, its location leaves a lot to be desired. The company wanted a complete "open work space," but all directors kept their offices, and some departments didn't opt in to the open concept, so some departments are cubed and some aren't. half of the office has no natural light, which is a bummer. Pay is way below standard for similar jobs in the similar field with similar sized company, you you have to fight for your pay.